Rochester is a census-designated place (CDP) in Thurston County, Washington, United States. It was founded in 1852, and the 2020 census recorded its population at 6,064. According to the United States Census Bureau, the CDP has a total area of 2.3 square miles, all of it land. Rochester Schools had 2,105 students registered in 2021-22 School Year.

Thurston County is a county located in the U.S. state of Washington. As of the 2020 census, its population was 294,793. The county seat and largest city is Olympia, the state capital.